Wednesday, 30 May 2012

A few weeks ago we spoke in this blog entry about the African odyssey of two satellite-tagged Extremadura Booted Eagles (Hieraaetus pennatus) from September 2011 to February 2012. Like the other tagged birds in other Spanish provinces our two Booted Eagles have now come home safe and sound and seem to have got down to the task of breeding. Their return journeys were as follows.

Luna (a female, No.5 on the map) left her stable wintering area in Mali on 16 March. After passing through Mauritania, Western Sahara and Morocco she crossed the Strait of Gibraltar on 1 April, thereafter returning more slowly to her breeding territory in Alburquerque (Badajoz), where she arrived on the 6th. In total a 2700 km journey in 21 days at an average of 130 km per day and the longest stages of 344 km and 323 km on 18 and 20 March, smack in the middle of the desert. Progress within Spain was much slower, with a maximum daily stint of 120 km. In 2012 she has built a new nest only 250 m from the one used in 2011, which fell down last winter (Ángel Sánchez, pers. com.).

Valiente (male, No.6 on the map) kicked off his trip from Nigeria on 19 March, then passing through Niger, Mali, Algeria and Morocco, crossing the Strait on 2 April and arriving back in La Roca de la Sierra (Badajoz) on 7 April. A long journey of 3500 km in 20 days, at a mean speed of 175 km per day and the longest stages of 420 and 418 km on 21 and 24 March. The longest day journey made in Spain was only 95 km. This was the swiftest moving of the six birds and one of the two with the most distant wintering area.

If we look at the whole set of six tagged birds (two in Badajoz and Madrid and one each in Castellón and Ávila) we find that the spring homecoming journey did not follow the same route as the autumn outgoing one, which was further west in all cases. The start day varied from 1 to 20 March (mean date of 13 March), the Strait crossing from 30 March to 11 April (mean date of 4 April) and the arrival on the breeding territory from 4 to 26 April (mean date of 10 April). The total distance covered ranged from 2725 to 3530 km (mean of 3095 km), the duration from 17 to 51 days (28 mean) and the average daily speed from 70 to 175 km (mean 126). Barring one bird that made the trip in two stages, stopping for a time in one of its two wintering areas, the rest came back directly, moving more rapidly through Africa and slowing down upon entering the Iberian Peninsula.

Thursday, 24 May 2012

Extremadura's last winter from December 2011 to March 2012 recorded an all-time low rainfall since records began. Luckily, April was fairly wet, saving a spring that was shaping up as dire. A succession of depressions swept in from the Atlantic in April 2012, rounded out by an explosive cyclogenesis on the 25th. The associated winds might have been responsible for the appearance in Extremadura of coastal migratory birds in the second half of April and first part of May. The phenomenon of coastal birds swept inland by winds usually occurs in winter, resulting in red-letter species for Extremadura like Great Northern and Black Throated Divers, Great Skua, Storm Petrel and Madeiran Storm Petrel. Spring episodes are pretty rare.

The standout example this spring has been the Common Tern (Sterna hirundo). Our April summary reports sightings in three different reservoirs, with maximums of ten birds at Guadiloba on 26 April (S. McAvoy/Birdwatch Ireland and G. Schreur), seven at Ahigal (A. Pacheco) and twelve at Portaje on 27 April(S. Mayordomo). On all occasions they were accompanied by Little Terns and Whiskered Terns, which may also have been wind driven but are more normal passage drop-ins inland. Subsequent visits to the same places did not turn up any Common Tern sightings. This brief influx, albeit modest, is the biggest recorded to date in Extremadura. In the eleven-year period running from 1998 to 2008 there were only five sightings of one or two Common Terms in April-May (without counting the breeding birds in Valdecañas Reservoir, the most recent in 2011).

Some coastal waders also turned up in greater-than-usual numbers in spring 2012, though relating these to the April storms is perhaps more a bit more fanciful. These included the Whimbrel (Numenius phaeopus), a very scarce but regular spring migrant in Extremadura. From 1998 to 2008 there were thirty sightings, the biggest being a flock of eight. In April 2012 it was seen in at least five sites, including the biggest flock ever recorded in Extremadura: 27 birds at Arrocampo Reservoir on 22 April (J. Julián). Much the same goes for the Sanderling (Calidris alba), with only 14 records involving 19 birds from 1998 to 2008 but with April 2012 records of six birds in three different places. That said, waders seem to be turning up in bigger numbers than usual in Extremadura this spring, this trend even continuing throughout May.

Monday, 21 May 2012

The Guardia Civil Nature Protection Service (Servicio de Protección de la Naturaleza de la Guardia Civil: SEPRONA) has arrested four people and accused another two of alleged involvement in an offence against the fauna. They are accused of setting snares and noose traps, forbidden hunting methods, for trapping threatened and protected species. The six plaintiffs are the gamekeepers and managers of three big-game hunting grounds in "Dehesa de los Barrancos", Peñalsordo (Badajoz).

The police caught the current gamekeeper red-handed setting out the snares and arrested him on the spot. The same forbidden practice was also used by the previous gamekeeper, who has also been arrested. Metal snares set on raptor perching points (rocks and tree trunks) were also found, some with remains of dead birds still attached. Among those identified were a Golden Eagle, four Eagle Owls, one Buzzard and an Egyptian Mongoose. The hunting grounds concerned fall within a protected area of the Natura 2000 network, listed as a Site of Community Interest (SCI) and Special Protection Area for Birds (SPA). The 2242 hectares of land occupied by the three hunting grounds were combed by police and agents from Extremadura's Environment Ministry on the days following the arrest. Sniffer dogs were used in the search to look for any poison bait but none was found. More than 30 snares and nooses were found, however, set up in passage areas, together with four unauthorised cage traps, one of them with live bait inside (a chicken). Many snares and wire nooses were also found in the gamekeeper's car and in the estate lodge.

Friday, 4 May 2012

The aforementioned website of the SEO/BirdLife bird migration project shows the movements of several different satellite-tracked species. The latest to be brought into the trawl are four Black-Shouldered Kites (Elanus caeruleus) tagged by the Regional Council of Extremadura (Junta de Extremadura). These birds are resident in Spain so their movements are not as spectacular as the migratory species but the tracking still offers valuable insights. We also phase in information furnished by Ángel Sánchez (Regional Environment Department of Extremadura) and Domingo Rivera (GPEX), and our thanks go to all the people working with this lovely raptor in Extremadura.

The first Black-Shouldered Kite, a young male called Chemi born in 2010, was tagged in Badajoz on 25.11.10. This makes it the project veteran. For a year it stuck close to the tagging area, normally staying within a radius of 1-5 km. It always used the same roost, shared with another 10-12 of its species plus 5-14 Marsh Harriers and 3-10 Hen Harriers. At the end of the first year, on 24.11.11, it set off westwards. By 04.12.11 it was 60 km away and 90 km away by the 23rd, in Portugal. On 14.01.12 it moved further into Portugal, arriving at the peak, though modest, distance of 170 km from its tagging site, returning quickly thereafter and remaining there up to the last record taken on 08.04.12.

The next two Black Shouldered Kites, a nesting pair of adults, were tagged in Talarrubias (northeast of Badajoz) on 08.04.11. The female (bird number 3, called Bellota) has stuck within a radius of 10 km nearly every day, barring two slightly further forays of 23 km and 17 km. The male (bird number 4, name of Pipo), strayed even less, to a maximum distance of 4 km up to 01.11.11 when the transmitter signals ceased. During 2011 this pair raised a first clutch of four chicks (ringed on 08.04.11), and a second clutch with three fledglings (ringed on 06.07.2011) and a third with another three young (located on 17.09.11). While the male looked after these last youngsters the female moved to a new territory close by (only 2150 m) where it paired with another male, laying another clutch of eggs, the fourth of the year, with four chicks on 25.10.2011. This means that the female Bellota produced 14 young throughout 2011 in four consecutive nests with hardly any rest between. The information on this bird ceased on 11.12.11.

Lastly, a fourth Black-Shouldered Kite (bird 2,called Campana), an adult female, was tagged on 16.06.11, again in Badajoz. One month later (19.07.11) it settled down near Sines, in the Portuguese district of Bajo Alentejo, where each day it made journeys of up to 10 km, with occasional forays up to 40 km. On 09.12.11, the last day with information, it remained in the same area.

Movements of the four Black Shouldered Kites (Elanus caeruleus). To the left, in pink, the male Chemi and in purple the female Campana. The point to the right represents the reduced movements of the pair formed by Bellota and Pipo.